Arc-light regulator



No. s|6,m. Patented nec. 2o, |898. w. J. KELLY.

Anc LIGHT neauLAron.

(Application led Jan. 29, 1898. Rllnlwed June 1, 1898.)

2 Sheets-Sheet l.

No Model.)

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No. 6|6,H|. Patented Dec. 20, |898.

W. J. KELLY.

ARI? LIGHT REGULATOR.

(Application led Jan. 29, 1896. Renewed June 1, 1898.) (No Model.) 2 Sheets-Sheet 2.

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.UNITED STATES PATENT OFFICE.

VILLIAM J. KELLY, OF BOSTON, MASSACHUSETTS.,

ARC-LIGHT REGULATOR.

SPECIFICATION forming part of Letters Patent No. 616,111, dated December 20, 1898. Application filed January 29, 1896. Renewed June 1, 1898. Serial No. 682,307. (No model.)

To all whom t may conce/"n:

Be it known that I, WILLIAM J. KELLY, residing in Boston, county of Suolk, and State of Massachusetts, have invented an Improvement in Arc-Light Regulators, of which the following description, in connection with the accompanying drawings, is a speciiication, like letters and figures on the drawings representing like parts.

rlhis invention has for its object to provide a regulator for automatic or self-feeding electric-arc lamps, and particularly arc-lamps of that class known as automatic focusing lamps, whereby the light emitted by the lamp may be gradually changed or reduced from a full light to a minimum light, and vice versa, which renders the focusing-lamp especially valuable in theaters and like places for producing scenic and other light effects.

Prior to this invention I am aware that incandescent electric lamps have been controlled or regulated so as to change the candle-power of the lamp from a maximum to a minimum light, and vice versa, which result is effected byinterposingin the circuit of the incandescent lamp a gradual and progressively-increasing resistance; but prior to my present invention I am not aware that a regulator has been made which is capable of producing the same results with an arc-lamp, and a regulator made upon the principle of an incandescent-lamp regulator cannot effect the desired results with an arc-lamp, owing to the fact that the arc formed between the carbon pencils or electrodes is of variable size, and therefore is of variable resistance.

By a long-continued series of experiments I have obtained a regulator for self-feeding or automatic focusing arc-lamps with which I am enabled to reduce theA candle-power of the said lamp from its maximum to its minimum light, and vice versa, Without causing the lamp to flicker or jump, which action would be detrimental for scenic purposes and might spoil the whole effect of the scene, the changes in the candle-power of the lamp being gradual and substantially imperceptible .and "the lamp remaining lighted at all times.v As a result of the long-continued series of experiments referred to I have discovered that an automatic arclamp,and especially an automatic focusing arc-lamp, may be regulated from full candle-power or maximum light to a dull-red or minimum light by gradually inte'rposing in the circuit of the lamp a series of resistances which vary substantially in accordance with the size or resistance of the arc-'fthat is to say, the resistance interposed in the circuit when the lamp is burning at full candle-power may be a series of gradually-increasing resistances interposed step by step, which reduces the candle-power to less than full light, and the next resistance or series of resistances interposed is less than the prior resistances, so that the are is held stationary, or it may be slightly increased, so as to form a new starting-point from which reduction takes place by interposing additional resistance. In other words, the reduction in the candle-power is effected by a series of increasing and diminishing resistances, corresponding to a series of pullingdown and building-up steps.

Electric circuits as now commonly connected with theaters usually carry a currentof about forty amperes, and the focusing arc-lamps as now commonly constructed and known to me operate at full candle-power with twenty amperes, and therefore the eurrent of forty amperes is reduced to approximately twenty amperes by a suitable resistance,which for the purpose of this invention I will designate as the fixed resistance, in order to distinguish it from the resistance forming the basis of this invention and which I prefer to designate as the variable resistance.

These and other 'features of this invention will be pointed out in the claims at the end of this' specification.

v Figure 1 is a top or plan view of one form of arc-regulator embodying this invention; Eig. 2, a front elevation of the regulator shown in Fig. 1, some of the resistance-coils being omitted; Fig. 3, a sectional detail te be referred to; and Eig. d a sectional view of a regulator,which may be supposed to be a developed view of the coils and contact-pieces or terminal steps shown in Fig. l, but arranged in a straight line to enable the invention to be more easily explained.

In the present instance I have shown the arc-light regulator in portable form, so that it may be easily transported from one place to another.

The arc-light regulator shown in Figs. l and 2 is provided with a supporting-frame, which may and preferably will be made as herein shown, and consists of the plates or slabs a a/ a2, preferably of slate or other suitable insulating material, which are tied together by suitable rods a3 a4, located at the corners of the said plates, as herein shown, the rods a3, as represented in Fig. 2, having their ends reduced in diameter and inserted through suitable holes in the plates a a', the said rods having screwed upon their lower ends suitable nuts a, and the rods a4 having in their opposite ends threaded sockets, into which extend the threaded upper ends of the rods a3 and retaining-bolts 0.7,' but instead of the particular form and construction of frameworl; herein shown l may use any other desired or suitable form of construction.

The plates a a in the present instance support a iixed resistance, shown as a coil as of wire wound about a post or block ai of slate or other suitable insulating material, and a variable resistance consisting, as here-r in shown, of a series or plurality of coils d10, of a character as will be hereinafter more fully described, and which may varyin number according to the degree of fineness of the arc regulation desired or required.

In the present instance the variable resistance is represented in Fig. 4: as composed 0f twenty-tive coils, numbered from l to 25, and each coil, as herein shown, is composed ot two legs or is made U-shaped and passed through suitable slots or openings in the plates a a.

Each coil al@ in practice is connected in series to its next adjacent coil, and for sake of simplifying the drawings the coils are represented as one continuous wire; but in practice each coil is preferably separate in order to obtain the desired resista-nce for each coil; but the said coils are soldered or otherwise electrically connected to have the effect of a continuous wire. The fixed-resistance coil a8 has one end connected to the coil No. l, and its other end is connected by the wire am to a binding-post or line-terminal als, suitably secured to the plate a2 and having connected to it one line or circuit wire am. The resistance-coil as has its other end connected with the iirst leg of the coil No. l and with a contact-piece or terminal l) by the wire O. The variable-resistance coils l to 25, inclusive, are connected in similar manner to contactpieces or terminals b to 525, inclusive, by wires marked ln to 25, inclusive, as clearly shown in Fig. 4t. These contact-pieces are supported upon the top plate a2 and are preferably arranged in the arc ot` a circle, as clearly shown in Fig. ll, each of the contactpieces, as herein shown, havinga stem or rod 50, which is extended down through a suitable hole in the top plate o? and is fastened by means of a clamping-nut 5l, the wire connection being effected, as represented in Figs. 3 and 4f, by means of a nut 52. Each of the contact-pieces or terminals l1 to li, inclusive, constitutes what I prefer to designate as a step of the regulator, andthe said contactpieces have cooperating with them one end of a movable member of the regulator or circuitcontroller, which member in the present instance is shown as a U-shaped metal piece UO, (see Figs. 2 and 3,) provided with extended ends Gl 62, the end Gl cooperating with the contact-pieces or terminals l) b, thc., and the other end 62 cooperating with a segmental plate G3, secured to the plate a2, as herein shown, by means of studs or posts (il, extended down through suitable holes in the plate a2 and secured thereto by nuts G5. In Fig. et l have represented the plate G3 as provided with three posts (Si. The segmental plate G3 is connected by the wire (55 to the binding-post GG, to which the opposite linewire 67 'is connected. The movable contact member G0 of the circuit-controller in the present instance is represented as carried by an arm 70, provided with lugs or ears 7l 72, between which the movable member GO is clamped by means of nuts 74C 75 on a threaded rod 76; butinstead of this particular manner of securing the movable member G0 to the arm I may employ any other desired or suitable construction. The arm 70 is represented iu the present instance as secured to a pivot-pin '78, extended through a sleeve 70, inserted through a hole in the plate d?, the said sleeve being clamped to the plate by means of a threaded ring or nut 80, and the pivot-pin 7S being clamped to the sleeve by means of a nut Sl, a washer S2 being interposed between the said nuts.

The pivot-pin 78 may be provided with a suitable handle or thumb-piece S3 Jfor convenience in turning the arm 70. ln the normal position of the arm 70 its movable member 60 is withdrawn from engagement with the contact-pieces or terminals connected to the resistances, in which position the lamp may be supposed to be cut out of circuit. Vhen the fixed resistance as is interposed in the arc-circuit, it will be understood, as above described, that the current flowing through the circuit is very considerably reduced-lor instance, from forty to twenty amperes. The circuit with the fixed resis tan ce may be traced as follows in Figs. l and lz from one linewire, as am, which may be regarded as thc positive line-wire, to thc binding-post al, thence by wire L12 through the fixed resistance as, wire O, to the contact-piece b, thence by the movable member GO to the terminal segment 63, thence by the wire G5 and bindingpost Gb' to the line-wire G7. lVhen the movable Contact memberO is in engagement with the contact or terminal l), the fixed resistance as is included in the circuit, as above de- IOO IIO

eie,1i1 i scribed, and the lamp at such time may be supposed to be operating at its maximum candle-power or full light.

In order to produce scenic eiiects, it is desir ble that the light should be decreased from full light toa dull-red or minimum light, or to such a dull light as will, in the case of an arc-lamp, be equivalent to substantially no light, yet leaving the lamp in the circuit and burning. To accomplish this result, I make use of a variable resistance consisting of a plurality of resistances, preferably in the form of coils, as herein shown, and in the present instance twenty-live in number. These coils are each of a different resistance, and by practical demonstration I have ascertained that a suitable resistance to first interpose in the circuit is .127 of an ohm, so that for the purpose of this invention the coil No. 1 of the Variable resistance may be supposed to represent .127 of an ohm. Coil No. 2 is a resistance equal to .O56 ot an ohm, so that When the contact member G0 is brought into engagement with the terminal or contact-piece b2 the total amount of variable resistance is equal to .183 of an ohm. This increase of resistance in the line-circuit reduces the candle-power of the focusing arc-lamp from full light; but the reduction is so slight as to be practically imperceptible, and a still further reduction is effected when the contact member 60 is brought into engagement with the terminal or contact b3, so as to in clude the coil No. 3 of the variable resistance, which coil is equal to .O40 of an ohm, making a total of .223 ot an ohm noW in the circuit in addition to the iixed resistance. 1t Will be understood that when the coil No. 3 of the variable resistance is brought into circuit with the lamp a less amountr of resistance is added than when the contact member 60 is moved from the contact-piece or terminal b to the contact member or terminal piece b2. In other Words, the second step corresponding to the contact-piece b2 adds to the line a resistance ot' .O56 of an ohm, While the third step adds to the line a less resistance-namely, .O40 of an ohm. Then the contact member 60 is brought to the fourth step, or into engagementwith the contact-piece b4, the coil No. 4is added to the circuit, which coil represents a resistance equal to .O71 of an ohm, and when brought into contact with the terminal b5 the coil No. 5 is added to the circuit, which equals .O87 of an ohm, and on the continued movement to the terminal o the coil G is brought into circuit, representing a resistance of .O48 of an ohm. rl'he seventh step of the resistance, represented by the engagement of the movable member GO with the contact or terminal 117, interposes the coil 7, representing .O63 of an ohm, and When brought into contact with the terminal 138 the coil 8 is added, representing .075 of an ohm, and when brought into engagement With the terminal b9 the coil 9 is added, representing .034 of an ohm, and when brought into contact with the terminal bw the coil 10 is added, representing .113 ot an ohm. The remaining coils 11 to 25, inclusive, represent, respectively,the following resistances, namelyzthe coil 11, .O97 of an ohm; coil 12, .275 of an ohm; coil 13, .115 of an ohm; coil 14, .231 of an ohm; coil 15, .161 of an ohm; coil 1G, .272 of an ohm; coil 17, .308 of an ohm; coil 18, .878 of an ohm; coil 19, 1.681 ohms; coil 20, .355 of an ohm; coil 21, .834 of an ohm; coil 22, .485 of an ohm; coil 23, .807 of an ohm; coil 24, .530 of an ohm, and coil 25, 1.828 ohms. 1t will be understood that as the circuit-con trolling member 60 is moved step by step from the position shown in full lines, Fig. 1, around into contact with the terminal Z325 the resistance represented by each successive coil 1 to 25, inclusive, is added to the iixed resistance as. For instance, when the contact member 60 is in engagement with the terminal 15, .381 ci' an ohm is added to the fixed resistance, and when the said contact member is in engagement With the terminalb10 the added variable resistance is .714, and when brought into contact with the terminal Z119 a total of 4.732 ohms is added to the fixed resistance, &c. It Will be seen that as the contact movable member 60 is brought from the full-light position in contact with the terminal b around into successive engagement with the terminals b' to 1925, inclusive, a gradual increase of resistance is interposed in the line-circuit, but that this resistance is not a progressive increase of the same amount for each step, but, on the other hand, the individual steps add apredetermined amount of resistance,which may vary from the amount of resistance controlled by the immediate adjacent steps-as, for instance, the step b2 adds .O56 of an ohm, While the step b3 adds only .O40 of an ohm, and its next adjacent step b adds .071 of an ohm, and the step b5 adds a further increase of .087 of an ohm, While the step h6 adds a decreased resistance of .O48 of an ohm, which increases again on bl to .O63 and on 198 to .O75 and decreases on b9 to .034, immediately again increasing to .113, then decreases to .097, die., according to the scale. This variation in the amount of resistance controlled by each individual step ot' the regulator is rendered necessary from the tact that the resistance of the arc between the carbon pencils or electrodes is a variable one, and the scale or schedule herein given is the result of practical demonstration. The theory or principle upon which the action of this `regulator is based is that when an increased resistance is added-as, for instance, between the steps 1 and 2 of .O56 of an ohm-the current flowing through the lamp is weakened, so that the carbons feed toward each other an imperceptible amount, yet suiiicient to slightly diminish the length of the arc, and consequently decrease the resistance due to the arc, Which diminution is substantially ofiset by the resistance interposed by the regulater, and the current iiowing through the magnet-coil controlling the feed of the car- IOS IIC

bons is maintained of such a strength as to keep the said magnet active or sufliciently strong to prevent its separating action upon the carbons being overcome by gravity, and this theory is evidently correct from the fact that if a substantially equal amount of resistance-namely, .O56 of an ohm-should be added by turning the movable contact member GO into engagement with the step b3 the strength of the coil would be diminished and the carbons vvould immediately fall toward each other so rapidly that on the addition of a feiv more steps-say three*the carbons would meet and the lamp Would be suddenly extinguished, owing, as I believe, to the fact that the successive interpositions of the same or a greater amount of resistance by the regulator would diminish the strength of the current more than would be offset by the decrease in the size of the arc, and the current flowing through the magnet Would not be sufficient to maintain the carbons separated, so as to keep the arc alive. Therefore instead of adding an equal or substantially equal amount of resistance on the next step-namely with the contact member GO in engagement with the step or terminal b3-a less amount is added, which diminishes the current imperceptibly, yet not sufficiently to materially affeet the feed of the carbons, and leaves the magnet in such condition as to be substantially unaffected by the interposition on the next step of a higher resistance-namely, .UTI-but to be suliiciently affected to feed the earbons slightly. In other Words, the arcregulator herein shovvn consists, essentially,of a variable resistance composed of separate or independent resistances of varying amounts.

In the present instance I have given one scale suitable for a regulator to be used in conjunction with a line-wire carrying originally fortyorapproximately forty amperes; but I do not desire to limit my invention to the particular schedule herein shown, as this schedule may vary under different conditions, that is, according to Whether the circuit carries a greater or a less amount of current, and also according to other conditions of the circuit, suoli as the resistance of thelamp,&c. g but the principle herein explained remains the same in any case-that is, in the present instance I have selected .127 of an ohm as a startingpoint for the firststep and then have added .056 for the second step, .0&0 for the third step, ttc.; but instead of starting with. 27 of an ohm as the first step I may select any desired resistance and add to it, in substantially the amounts designated for the various steps, additional resistances, so that the total amount of resistance interposed in the circuit undcr such conditions Would vary from the total amount herein given. It will be noticed that each of the last feu' steps of the regulator-namely,from bw to Z125-adds a substantially large amount of resistance as the carbon pencils approach in close proximity to each other; but, if desired, the amount of the resistance added by each of these steps may be made smaller and the number of steps correspondingly increased.

In the present instance I have shown the arc-regulator as embodied in a portable form, with the fixed resistance carried by the supporting-frame; but I do not desire to limit my invention in this respect, asin some placesfor instance, in theaters-it may be found desirable to place the xed resistance in a separate frame from the variable resistance; but when so constructed the fixed resistance vvill be coupled or electrically connected with the variable resistance after the manner hercin shown.

From the above description it will be seen that the gist of this invention and that which ena-bles the automatic arc focusing-lamp to be brought from full or maximum light down to a dull-red or minimum light without flickering, jumping of the carbons, and with an imperceptible graduation of the light, and vice versa, resides in the variable resistance, the coils or steps of which vary from each other after the manner above described.

In practice I have provided the regulator with an additional contact-piece d, which is blank or disconnected from the line-circuit and with Which the movable contact member may be engaged whenever it should be desired to completely eut out the arc-lamp. This contact-piece CZ is in close proximity to the contact-piece or terminal b2, so that the lamp may go from a dull red to total darkness and may be brought from total darkness gradually up to full light. I may prefer to arrange the contact-steps or terminals b to Z125, inclusive, in the are of a circle, as shown in Fig. l, and to employ in conjunction therewith a rotatable contact member, such as GO; but I do not desire to limit my invention in this respect, as the contact-steps or terminals maybe otherwise arranged-as, forinstance, in a straight line, as represented in Fig. L and the movable cont-act member may be moved over the said contact-steps or termi- 'nals in a straight line.

I claim` l. In a regulator for automatic arc-lights, the combination with a variable resistance composed of a series of resistances,increasing and diminishing irregularly as described, to enable the arc-lamp to be regulated Without interfering with its functions, and a circuit` controller cooperating with the said variable resistances, substantially as described.

2. In a regulator for automatic arc-lights, the combination with a supporting-frame provided With a series or plurality of contacts or terminals, of a series of resistances connected in circuit With each other and to the said contacts or terminals, the resistance connected to some contacts being less than that connected to other contacts on opposite sides of them, and a circuit-controller cooperating with said contacts or terminals, substantially as described.

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3. In a regulator for automatic are-lights, the combination With a supporting-frame provided With a series of Contacts or terminals, a movable circuit-Controllercoperatingwith said contacts or terminals, a series of Variable increasing and diminishing resistanoes connected to the said contacts or terminals and controlled by the movable circuit-controller and a iixed resistance carried by the said 4frame and eonneeted to one of the said eontaets or terminals but not under the control of the movable circuit-Controller. substantially as and for the purpose specified.

e. In a regulator for automatic are-lights, the Combination with a plurality or series of contacts or terminals, anda coperating movable circuit-controller, of a plurality of resistanees connected to the said contacts or terminals and of varying resistanees, lower or diminishing resistanees being connected to contacts or terminals intermediate of Contaei's or terminals to which higher or increasing resistanees are connected, substantially as and for the purpose speeiiied.

5. A regulator for automatic arc-lights provided with a resistance consisting of a plurality of Variable increasing and diminishing resistanees connected in sequence to eieet the regulation of the are-light from full light to substantially no light and Vice versa Withoutinterfering with the functions of the lamp in its regulation, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subseribin g Witnesses.

VILLIAM J. KELLY.

iVitnesseS:

JAS. H. CHURCHILL, J. MURPHY. 

